Spinnerette manufacture



Nov. 20, 1956 .1. A. CUPLER, 2.77 3

SP INNERE'TTE MANUFACTURE Filed Dec. 31, 1953 FIG. I. FIGZ.

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Unite States Patent 2,770,987 SPINNERETTE MANUFACTURE John A. Cupler H,Cumberland, Md. Application December 31, 1953, Serial No. 401,601

7 Claims. c1. 76107) The present invention relates to improvements inthe manufacture of spinnerettes and is particularly related toimprovements over the procedures set forth in U. S. Letters Patent No.2,618,989, dated November 25, 1952, issued to John A. Cupler II.

Here again, it is of fundamental importance that the intersection of thecapillary portion of the extrusion orifice with the discharge surface ofthe spinnerette be as sharp as possible. It is also important that thefinish of the wall of the capillary portion be relatively smooth, thatthe length of all elements of the cylinder defined by the capillaryportion be the same and it becomes increasingly important that thelength of the capillary portion with respect to its diameter be large.

The present method of finishing the discharge surface of a spinnerettecontaining an orifice comprises inserting a plug having a complementarycross section through the orifice to project beyond the surface,applying a compacting force to the surface contiguous to the plug,abrading the plug and surface contiguous thereto until they becomesubstantially coplanar, and mechanically removing the plug from asurface opposed to the discharge surface. The composition of thespinnerette is preferably an austenitic ferrous alloy capable of coldworking so that the grain size of the spinnerette contiguous to the plugis reduced before the abrading operation. This becomes important sinceit has been found that the sharpness of the intersection between thecapillary portion of the orifice and the discharge surface is a functionof the grain size at that intersection. This reduction of the grain sizecan be achieved effectively by a cold working or coining operation inthe area involved.

Removal of the plugs following the abrading operation is preferablyeffected by applying pressure to only a portion of the area of theabraded end of the plug to remove it from a surface. opposed to thedischarge surface. It has been found that this method of removal avoidsdistortion of the material which might otherwise be produced. As amatter of fact, it has been found that by chemically etching the abradedend of the plug prior to the application of pressure, removal of theplug is greatly simplified and damage to the spinerette minimized.Various acids are well suited for the purpose.

A more complete understanding of the invention will follow from adescription of the accompanying drawing wherein:

Fig. 1 is a fragmentary sectional elevation of a blank which hasreceived a counterbore;

Fig. 2 is a fragmentary sectional elevation of the same blank after ithas been drilled to receive the capillary portion of the orifice;

Fig. 3 is a fragmentary sectional elevation depicting a combinedbroaching and coining operation;

Fig. 4 is a fragmentary sectional elevation of the blank following theoperation of Fig. 3;

Fig. 5 is a fragmentary sectional elevation of the blank with a pluginserted through the orifice;

Fig. 6 is a fragmentary sectional elevation showing the 2,770,987Patented Nov. 20, 1956 use of a thermoplastic material to secure theplug in place and showing a fixture in position;

Fig. 7 is a fragmentary sectional elevation showing a compactingoperation;

Fig. 8 is a fragmentary sectional elevation depicting an abradingoperation; and

Fig. 9 is a fragmentary sectional elevation depicting the removal of theplug from the blank.

The blank 10 of Fig. 1 has received a countersink or counterbore 12 fromthe inlet surface 14. By the next operation, a drill 16 is applied tothe bottom wall 18 of the counterbore to produce the capillary portion20 intersecting the discharge surface 22. This may be followed by acombined operation by means of a tool 24 which is forced completelythrough the capillary portion 20 to impart relative smoothness to thewall of the capillary portion and if desired, a very slight radius atthe intersection of the capillary portion and the bottom of thecounterbore. Incidentally, it will be noted that the bottom of thecounterbore has been depicted as perpendicular to the axis thereof whichpermits the elements of the cylinder defining the capillary portion tobe of equal length even though the axis of the capillary portion may besomewhat eccentric with respect to the axis of the counterbore. It'ispreferred that the angle defined by the slope of the bottom wall of thecounterbore adjacent its intersection with the capillary portion and theaxis of the capillary portion have a value between 65 and so that thelengths of the elements of the cylinder defining the capillary portionwill always be substantially equal. Where the wall of the counterbore isinclined to a greater degree suflicient to provide an uninterruptedflow, the danger of distortion of the capillary portion becomes serious.

After the tool 24has been retracted from the blank, the semi-finishedarticle' assumes the form such as that depicted in Fig. 4. A suitableplug 26 is now introduced from the inlet surface 14 so that its end 28projects beyond the discharge surface 22. If desired, this plug mayperform the broaching and coining operation rendering it possible toeliminate one of the manufacturing steps already described. The plug issecured in position by its frictional engagement alone, and/ or by theapplication of a thermoplastic body 30 to the inlet surface of theblank, filling the portion of the counterbore surrounding the plug asshown in Fig. 6. A suitable fixture 32 has been indicated assuperimposed upon the thermoplastic material and containing recesses 34for reception of a driving tool.

The next operation, depicted in Fig. 7 may be accomplished by means of acompacting tool 36 containing a bore 38 longer than the projecting endof the plug 26 but closely complementing its cross section. By theapplication of pressure or compacting force to the tool 36 in thedirection of the arrow 40, the grain size of the blank contiguous to theplug is reduced. This result follows naturally from the cold working ofaustenitic ferrous alloys of well known types.

Compositions of the blanks preferred for the purposes contemplatedherein include:

8 to 20% nickel 17 to 35% chromium 2 to 3% molybdenum Not more than 2%manganese Not more than 0.1% carbon Balance essentially iron Highercorrosion resistance will be obtained with alloys of the type:

8 to 14% nickel 17 to 19% chromium 2 to 3% molybdenum Balanceessentially iron Higher heat resistance characteristics will result withan alloy of the type:

20% nickel 25% chromium Balance essentially iron After the reduction ofgrain siZe by compacting or cold working as depicted in Fig. 7, theabrading operation is performed against a lapping and/ or polishingsurface 42 by means of a driving head 44 providing pins 46 received inthe recesses 34. The abrading operation is continued until the dischargesurface and plug are substantially coplanar whereupon the driving head44, fixture 32 and thermoplastic material 30 are removed. The onlyremaining operation is the removal of the plug from the orifice. Theactual physical removal may be preceded by the application of a suitableacid to the abraded end of the plug momentarily and then washing theacid away, thus performing an etching operation which removes a smallamount of the material from the end of the plug without apparentlyaffecting the surface of the blank itself. This permits an operator tolocate the end of the plug more readily and thereby facilitate itsremoval from the blank. A minimum of distortion of the product isobserved when the plug is pushed from the blank rather than pulled fromit. Accordingly, as

depicted in Fig. 9, a punch 48, of somewhat smaller.

cross section than that of the plug itself is applied to the abraded endof the plug and moved in the direction of the arrow 5i) to push the plugout of the blank at the inlet surface 14.

The resulting product, which would appear substantially as that depictedin Fig. 4, achieves a linearity of intersection between the capillaryportion 20 and the discharge surface 22 never before achieved in thisart. The elements defining the cylinder of the capillary portion 20 areequal because of the configuration of the bottom of the counterbore. Themultiple extrusion orifices almost invariably formed in such blanks canbe controlled by this method so as to have capillary portions which aresubstantially identical. All of these features contribute to the greatimprovement in the filaments produced with these spinnerettes.

Although the drawings have depicted a rather specific sequence ofoperations, and whereas many variations contemplated have not beendiscussed, the breadth of the invention should not be restricted beyondthe scope of the appended claims.

I claim:

1. A method of finishing the discharge surface of a spinnerettecontaining an orifice and having a composition whose grain size isreduced by cold Working, comprising inserting a plug having acomplementary cross section through said orifice to project beyond saidsurface, applying a compacting force to said surface contiguous to saidplug sufiicient to deform said surface, abrading said plug and saidsurface contiguous thereto until they become substantially coplanar, andmechanically removing said plug from a surface opposed to the dischargesurface.

2. A method of finishing the discharge surface of an austenitic ferrousalloy spinnerette containing an orifice,

comprising inserting a plug having a complementary cross section throughsaid orifice to project beyond said surface, reducing the grain size ofsaid spinnerette by deforming said surface contiguous to said plug,abrading said plug and said surface contiguous thereto until they becomesubstantially coplanar, and mechanically removing said plug from asurface opposed to the discharge surface.

3. A method of finishing the discharge surface of a spinnerettecontaining an orifice, comprising inserting a plug having acomplementary cross section through said orifice to project beyond saidsurface, cold working and deforming said surface contiguous to saidplug, abrading said plug and said surface contiguous thereto until theybecome substantially coplanar, and mechanically removing said plug froma surface opposed to the discharge surface.

4. A method of finishing the discharge surface of a spinnerettecontaining an orifice, comprising inserting a plug having acomplementary cross section through said orifice to project beyond saidsurface, abrading said plug and said surface contiguous thereto untilthey become substantially coplanar, and applying pressure to only aportion of the area of the abraded end smaller than the area of the endof said plug to displace said plug, and removing said plug from asurface opposed to the discharge surface.

5. A method of finishing the discharge surface of a spinnerettecontaining an orifice, comprising inserting a plug having acomplementary cross section through said orifice to project beyond saidsurface, abrading said plug and said surface contiguous thereto untilthey become substantially coplanar, chemically etching only the abradedend of said plug, applying pressure to a portion of said end smallerthan the area of the end of said plug, and removing said plug from asurface opposed to the discharge surface.

6. A method of making a spinnerette comprising drilling a blank of anaustenitic ferrous alloy to form an orifice, polishing said orificeadjacent the discharge surface of the blank, inserting a plug having acomplementary cross section through said orifice to project beyond saidsurface, reducing the grain structure of said blank by deformation ofsaid surface contigious to said plug, abrading said plug and saidsurface contiguous thereto until they become substantially coplanar, andmechanically removing said plug.

7. A method of making a spinnerette comprising drilling a blank of anaustenitic ferrous alloy to form an orifice, polishing said orificeadjacent the discharge surface of the blank, inserting a plug having acomplementary cross section through said orifice to project beyond saidsurface, compacting said blank contiguous to said plug sufficient todeform said surface, abrading said plug and said surface contiguousthereto until they become substantially coplanar and pushing said plugfrom said discharge surface towards an opposed surface.

References Cited in the file of this patent UNITED STATES PATENTS902,322 Porter Oct. 27, 1908 915,762 Grivolas Mar. 23, 1909 2,618,989Cupler Nov. 25, 1952

